Improved shallow depth cut diamonds

ABSTRACT

The invention is directed to shallow pavilion, cut diamonds having excellent optical characteristics. The shallow pavilion cut diamonds of the invention have a table with a table plane and a girdle. The cut diamonds have a shape and configuration that result in a specific total depth percentage, a specific crown height percentage, a specific girdle height percentage and a specific table percentage. A crown surface is located between the table and the girdle and extends in a crown angle to the table plane. A pavilion surface extends at a pavilion angle relative to the table. The pavilion surface includes a plurality of substantially planar main pavilion facets, each of which extend from the girdle to a pointed culet defining the bottom most portion of the cut diamond. The crown angle is in the range of between about 29 degrees to about 36 degrees, and the pavilion angle is in the range of between about 15 degrees and about 34.5 degrees. The shallow pavilion, cut diamonds of the invention may be either round shaped cut diamonds or fancy shaped cut diamonds.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase application of PCT/US17/54798filed Oct. 2, 2017, and claims priority to U.S. application Ser. No.15/283,194 filed Sep. 30, 2016, which are incorporated herein in theirentirety by reference.

BACKGROUND OF THE INVENTION

The invention is directed to finished cut diamonds that have bothexcellent optical characteristics and exceptionally high yield for thefinished stones. More specifically, the present invention provides bothround and fancy shallow pavilion cut diamonds with exceptional opticalcharacteristics.

In the United States market, the round, brilliant cut has been the rounddiamond market standard since it was developed by Marcel F. Tolkowsky in1919. The round, brilliant cut and most other popular round cut diamondsinclude a relatively tall crown height, steep pavilion angle, and hightotal depth percentage. As a result, the girdle diameter of these stonesis relatively small in comparison to their pavilion depth and the totaldepth of the stone. While prior art round, brilliant cut diamonds haveexcellent optical characteristics, their tall crown height requires arelatively high stone weight for a cut diamond of a given girdlediameter. For some rough diamond stones, this tall crown height canresult in a higher than optimal loss of weight during the cutting andpolishing process when converting the rough diamonds to finished stones.

Some rough diamonds, having a depth of less than about 3 mm (known inthe trade as “flat stones”), are too shallow for cost efficient cuttinginto round, brilliant cut diamonds. The strong market preference fordeep pavilion round, brilliant cut finished diamonds has rendered suchflat stones (low overall depth) nearly unmarketable for use in creatinghigh optical quality round, brilliant cut finished diamonds. One of thereasons round, brilliant cut diamonds utilize steep pavilion angles wasthe belief that deep pavilions were necessary to avoid the opticalcharacteristic known in the trade as the “fish eye effect.” This opticaleffect occurs when light loss from within one or more of the diamond'sinternal surfaces are sufficient that the table, when viewed from above,includes one or more areas that are substantially darker than the restof the diamond. Such darkened “fish eye” areas are considered to behighly undesirable in a cut, finished diamond.

For similar reasons, prior art fancy cut diamonds (non-round shaped)have traditionally had relatively steep pavilion angles in order toavoid inferior optical characteristics, such as the “fish eye” effect,in the finished fancy diamond. Similar to the case with the prior artround brilliant cut diamonds, the steep pavilion angles and relativelytall crown heights of the prior art fancy cut diamonds resulted inhigher than optimal loss of weight (low cut weight yield) during thecutting and polishing processes.

Surprisingly, the applicant has found that cut diamonds with relativelyshallow pavilion angle cuts combined with the other parameters set forthbelow have optical characteristics that are at least equivalent to, andoften superior to, the prior art standard fancy cuts and round,brilliant cut diamonds. Moreover, due to their shallow pavilion depth,the cutting and polishing weight loss is significantly reduced for manyrough stones. Further, the higher proportion of girdle diameter (roundcut) or surface area (fancy cut) to stone weight provides the visualimpression to consumers that the stone is significantly larger than itsactual carat weight. Moreover, the applicant has discovered that round,cut diamonds with excellent optical characteristics may be costefficiently cut from “flat stones,” which can further reduce the cost ofthe round, shallow pavilion cut stones of the invention relative to theround, brilliant cut diamonds of the prior art.

It is an object of the invention to provide a shallow pavilion angleround, cut diamond that has good sparkle characteristics.

It is an object of the invention to provide a shallow pavilion anglefancy, cut diamond that has good sparkle characteristics.

Another object of the invention to provide a shallow pavilion cutdiamond with enhanced light reflection amplification.

It is another object of the invention to provide a cut diamond with goodoptical characteristics that appears, when viewed from above, to belarger/heavier than its actual size/weight of the cut stone.

It is a still further object of the invention to provide round, cutdiamonds that have significantly higher cut weight yield relative to theprior art round, brilliant cut diamonds.

It is another object of the invention to provide high optical qualityround cut, diamonds from so called rough “flat stone” diamonds.

SUMMARY OF THE INVENTION

In a first preferred embodiment, the invention includes a cut diamondhaving a round shape. The round cut diamond including a table having atable plane and a substantially annular girdle. The round cut diamondhas a shape and configuration that results in a specific total depthpercentage, a specific crown height percentage, a specific girdle heightpercentage and a specific table percentage. A crown surface is locatedbetween the table and the substantially annular girdle and extends in acrown angle to the table plane. A pointed culet defines the bottom mostportion of the round cut diamond. A pavilion surface extends at apavilion angle relative to the table. The crown angle is in the range ofbetween about 29 degrees to about 36 degrees, and the pavilion angle isin the range of between about 25 degrees and about 36 degrees.

The invention further includes fancy cut diamonds with a table having atable plane and a girdle having a non-circular circumference. The fancycut diamonds have a shape and configuration that results in a specifictotal depth percentage, a specific crown height percentage, a specificgirdle height percentage and a specific table percentage. A crownsurface is located between the table and the girdle and extends in acrown angle to the table plane. A pavilion surface extends at a pavilionangle relative to the table. The pavilion surface includes a pluralityof substantially planar main pavilion facets each of which extend fromthe girdle having a non-circular circumference to a pointed culetdefining the bottom most portion of the cut diamond. The crown angle isin the range of between about 29 degrees to about 36 degrees and thepavilion angle is in the range of between about 15 degrees and about34.5 degrees. For the purposes of this application, the phrase “fancycut diamond” includes all cut diamond shapes that are other thansubstantially round (when viewed from above), shaped diamonds.

In another aspect, the present invention is further directed to cutdiamonds having a table with a table plane and a girdle. The cutdiamonds have a shape and configuration that results in a specific totaldepth percentage, a specific crown height percentage, a specific girdleheight percentage and a specific table percentage. A crown surface islocated between the table and the girdle and extends in a crown angle tothe table plane. A pavilion surface extends at a pavilion angle relativeto the table. The pavilion surface includes a plurality of substantiallyplanar main pavilion facets, each of which extend from the girdle to apointed culet defining the bottom most portion of the cut diamond. Thecrown angle is in the range of between about 29 degrees to about 36degrees, and the pavilion angle is in the range of between about 15degrees and about 34.5 degrees. The cut diamonds in accordance with thisaspect of the invention may be either round shaped cut diamonds or fancyshaped cut diamonds.

DESCRIPTION OF THE DRAWINGS

The organization and manner of the structure and function of theinvention, together with the further objects and advantages thereof, maybe understood by reference to the following description taken inconnection with the accompanying drawings, and in which:

FIG. 1 is a top plan view of a round, shallow pavilion diamond inaccordance with a first embodiment of the invention;

FIG. 2 is a bottom plan view of a round, shallow pavilion diamond of theinvention in accordance with the embodiment of FIG. 1;

FIG. 3 is a side plan view of a round, shallow pavilion diamond of theinvention in accordance with the embodiment of FIG. 1;

FIG. 4 is a side plan view of a prior art round, brilliant cut diamond;

FIG. 5 is a side plan view of a prior art round, brilliant cut diamondillustrating its measured light reflecting and refracting properties;

FIG. 6 is a side plan view of a round, shallow pavilion diamond of theinvention illustrating its measured light reflecting and refractingproperties;

FIG. 7 is a top plan view of a first cushion shaped, shallow paviliondiamond in accordance with a second embodiment of the invention;

FIG. 7A is a top plan view of an alternate crown facet arrangement for acushion shaped, shallow pavilion diamond in accordance with a secondembodiment of the invention;

FIG. 7B is a top plan view of a second cushion shaped, shallow paviliondiamond in accordance with a second embodiment of the invention;

FIG. 7C is a top plan view of an alternate crown facet arrangement for acushion shaped, shallow pavilion diamond in accordance with a secondembodiment of the invention;

FIG. 7D is a top plan view of an alternate crown facet arrangement for acushion shaped, shallow pavilion diamond in accordance with a secondembodiment of the invention;

FIG. 8 is a bottom plan view of the cushion shaped, shallow paviliondiamond of the invention in accordance with the embodiment of FIG. 7;

FIG. 8B is a bottom plan view of the cushion shaped, shallow paviliondiamond of the invention in accordance with the embodiment of FIG. 7B;

FIG. 9 is a side plan view of the short side of the cushion shaped,shallow pavilion diamond of the invention in accordance with theembodiment of FIG. 7;

FIG. 10 is a top plan view of heart shaped, shallow pavilion diamond inaccordance with a third embodiment of the invention with the pavilionfacets shown with phantom lines;

FIG. 10A is a top plan view of second heart shaped, shallow paviliondiamond in accordance with a third embodiment of the invention with analternate arrangement of crown facets and an alternate arrangement ofpavilion facets shown with phantom lines;

FIG. 11 is a side plan view of the short side of the heart shaped,shallow pavilion diamond of the invention in accordance with theembodiment of FIG. 10;

FIG. 12 is an enlarged, side plan view of the long side of the heartshaped, shallow pavilion diamond of the invention in accordance with theembodiment of FIG. 10;

FIG. 13 is a top plan view of a pear shaped, shallow pavilion diamond inaccordance with a fourth embodiment of the invention;

FIG. 14 is a bottom plan view of a pear shaped, shallow pavilion diamondin accordance with the embodiment of FIG. 13;

FIG. 14A is a top plan view of a pear shaped, shallow pavilion diamondillustrating an alternate arrangement of pavilion facets for a diamondin accordance with the third embodiment of the invention;

FIG. 15 is an enlarged, side plan view of the long side of the pearshaped, shallow pavilion diamond of the invention in accordance with theembodiment of FIG. 13;

FIG. 16 is a side plan view of the short side of the pear shaped,shallow pavilion diamond of the invention in accordance with theembodiment of FIG. 13;

FIG. 17 is an enlarged, top plan view of an oval shaped, shallowpavilion diamonds in accordance with a fifth embodiment of theinvention;

FIG. 18 is an enlarged, top plan view of an oval shaped, shallowpavilion diamond with the pavilion facets shown in phantom lines inaccordance with the embodiment of FIG. 17;

FIG. 19 is a side plan view of the long side of the oval shaped, shallowpavilion diamond of the invention in accordance with the embodiment ofFIG. 17; and

FIG. 20 is a side plan view of the short side of the oval shaped,shallow pavilion diamond of the invention in accordance with theembodiment of FIG. 17.

DETAILED DESCRIPTION OF THE DRAWINGS

In accordance with a first embodiment of the invention, FIGS. 1-3 show ashallow pavilion, round cut diamond 20 having a table 22, a crown 24extending downwardly from the table 22, a girdle 32 below the crown 24,and a pavilion 26 extending downwardly from the girdle 32. The surfaceof the pavilion 26 narrows in width to a pointed culet 30. FIG. 3 showsthat the pavilion 26 extending at a distinct pavilion angle (<P)relative to the plane of the table (or to a line parallel to the tablepassing through the girdle) of the diamond stone. Similarly, the crownangle (<C) is also indicated on FIG. 3. The crown 24 and pavilion 26portions of the round, shallow pavilion diamond 20 are separated by anarrow, substantially annular girdle portion 32. The girdle 32 ispreferably either a polished single annular surface or can bemulti-faceted with the multiple small facets approximating an annularsurface (not shown).

More specifically, as can be seen in FIGS. 1-3, the crown 24 of theround cut diamond 20 of the invention is comprised of a total ofthirty-three facets, including a single table facet 22, eight bezelfacets 21, eight star facets 23, and sixteen upper girdle facets 25. Thepavilion 26 comprises a total of twenty-five facets including sixteenlower girdle facets 27, eight main pavilion facets 29, and a singlepointed culet 30 as shown in FIG. 3. The crown angle is measured betweenthe surface of each of the bezel facets 21 and the plane of the table 22(average of each measured angle for the bezel facets). The pavilionangle is measured between the plane of the table 22 and main pavilionfacets 29. The pavilion 26 narrows to a pointed culet 30, that is apreferably “true point,” that is, a very sharp point as shown in FIG. 3.However, the point culet 30 may be a less sharply pointed culet (notshown), which would have either a slightly larger flattened surface areathan a “true point” or a slightly rounded or beveled surface defining aportion of such a culet.

In marked departure from the prior art round, brilliant cut diamonds,the present inventor has discovered that at least equivalent reflectionpattern can be obtained by providing a round, shallow pavilion diamondwith a very shallow pavilion, namely by forming the pavilion angles inthe range of twenty five to thirty six degrees, preferably thirty tothirty two degrees, as opposed to the conventional pavilion angles whichare in the range of 40 to 43 degrees. Put another way, when matched fordiamond diameter and viewed from above, the round, shallow paviliondiamonds of the invention provide a stone with the same top down viewand at least equivalent optical characteristics to the prior art round,brilliant cut diamonds of significantly higher carat weight. The round,shallow pavilion diamonds have a carat weight that is between 10% and20% (typically 16%-18%) less than a matched diameter prior art, roundbrilliant cut diamonds. Furthermore, the shallow pavilion diamonds ofthe present invention can realize unexpected brilliance and lightamplification characteristics with total depth percentage in a rangefrom about twenty five percent to about fifty percent. This contrastwith the total depth percentage range of between 55 to 64 percent forprior art round, brilliant cut diamonds. The maximum and minimum crownangles for the shallow pavilion, round diamonds of the invention arebetween about thirty two degrees and thirty six degrees with thepreferred crown angles ranging from thirty three to thirty five degrees.

Table 1 below provides the relevant parameters for the round, shallowpavilion diamonds of the invention, indicating in each instance aminimum value, a maximum value and a preferred range.

TABLE 1 ANGLE AND PERCENTAGE PARAMETERS FOR ROUND CUT DIAMONDS PARAMETERMINIMUM PREFERRED RANGE MAXIMUM Crown Angle° 29 33-35 36 Crown Height %7  9-12 15 Girdle Height % 1 1.5-5  7 Pavilion Angle° 25 30-33 36 Table% 55 66.5-85  85 Total Depth % 25 35-47 50

FIGS. 5 and 6 illustrate the measured light reflection patterns from ashallow pavilion, round cut diamond of the first embodiment of theinvention (FIG. 6) and from a conventional prior art, round brilliantcut diamond (FIG. 5). In the round, brilliant cut diamond of the priorart shown in FIG. 5, a ray of light that strikes the tableperpendicularly hits the pavilion at one side, is then reflected to theopposed pavilion side and eventually reflected back out through thetable with only a small portion of the light traversing the volumebetween the other internal surfaces of the diamond. As a result, thetotal light transmitted back from the table for the OGI Systems Ltd.CFire™ optical performance test is 68% as can be seen in FIG. 5.

In contrast to the prior art, the light pattern for round, shallowpavilion cut diamond 20 of the invention, follows a path whereby lightis reflected from one pavilion surface to an opposed crown surface, thenanother pavilion surface, then to the table, then back to a pavilionsurface, then to the crown, then to an opposed pavilion surface and onlythen out to the table. This light pattern, with light rays beingrepeatedly reflected and refracted between many diamond surfaces createsan unexpectedly brilliant light display for a shallow pavilion, roundcut diamond. As a result of the repeated reflection and refraction, thelight transmitted from the table 22 of the shallow pavilion, rounddiamond 20 during the OGI Systems Ltd. CFire™ optical performance testis an impressive 69% as illustrated in FIG. 6. This is slightly betterthan for the round, brilliant cut diamond of FIG. 5 even though whenmatched for diameter conventional brilliant cut, diamonds weigh between10-20% more than the round, shallow pavilion diamond of the invention.The crown angle, crown height, girdle height, pavilion angle, tablepercentage and total depth for the shallow pavilion stone 20 all fallwithin the ranges set forth in Table 1.

The crown angle for the prior art round, brilliant cut diamond shown inFIG. 4 is about thirty five degrees and the pavilion angle is aboutforty one degrees. The total depth percentage for the prior art diamondof FIG. 4 is about 60% and is calculated as the ratio of the heightdivided by the width (diameter) of the stone. The table percentage forthe prior art diamond of FIG. 4 is about 53% and is calculated relativeto the diameter of the stone. The corresponding values for a round,shallow pavilion cut diamonds of the present invention are set forth inthe Table 1 above. As can be discerned from a comparison of the sideview shown in FIG. 3 and FIG. 4, the shallow pavilion, round diamond 20of the invention has a significantly more shallow total depth, whichresults from the shallow pavilion angles of the diamond of the presentinvention. As a result of utilizing that shallow pavilion angle andother parameters set forth in Table 1, the applicant has found thatfinal cut and polished stones of the invention routinely provide a yieldof between fifty to fifty-five percent relative to the rough diamondsfrom which they are cut. In many cases, the so called rough “flatstones” may be utilized to create the shallow pavilion, round cutdiamonds of the invention, thereby further reducing the cost of anexcellent optical quality round diamond of a given diameter. Incontrast, the prior art round, brilliant cut diamond (e.g., as shown inFIG. 4) have a typical finished cut/polished stone to rough stone yieldsin the range from about thirty-five percent to about forty percent andusually required more expensive deep (cubic) raw stones.

Pointed Culet, Fancy Cut Shallow Pavilion Stones

In accordance with another aspect of the invention, a variety of shallowpavilion, fancy cut diamonds are provided four embodiments of which areillustrated in FIGS. 7-20. The four illustrated embodiments of theshallow pavilion, fancy cut diampngs include cusion shaped, cut diamonds120, 120B (FIGS. 7-9B); heart shaped, cut diamonds 220, 220A (FIGS.10-12); pear shaped, cut diamonds 320 (FIGS. 13-16); and oval cutdiamond 420 (FIGS. 17-20), respectively. While the illustrations hereinshows the four most common fancy cut diamond shapes, the shallowpavilion, pointed culet, fancy cut diamonds of the invention may also beasher cut, calf cut, emerald shaped, half-moon shaped, marquise,princess cut, radiant cut, straight baguette, and trillion shaped. Table2 below provides the relevant parameters for the shallow pavilion, fancycut diamonds of the invention, indicating in each instance a minimumvalue, a maximum value and a preferred range.

TABLE 2 ANGLE AND PERCENTAGE PARAMETERS FOR FANCY CUT DIAMONDS PARAMETERMINIMUM PREFERRED RANGE MAXIMUM Crown Angle° 29 30-35 36 Crown Height %7  9-12 15 Girdle Height % 1 1.5-5  7 Pavilion Angle° 15 22-33 34.5Table % 50 60-85 90 Total Depth % 25 33-43 55

Turning to the cushion shaped, shallow pavilion diamond 120 of theinvention shown in FIG. 7-9, the diamond 120 has a table 122, a crown124 extending downwardly from the table 122, a girdle 132 located belowthe crown 124, a pavilion 126 extending downwardly from the girdle 132,the pavilion 126 surface narrowing in width to a pointed culet 130. FIG.9 shows that the pavilion 126 extends at a distinct pavilion angle,within the range set forth in Table 2 relative to the plane of the table(or to a line parallel to the table passing through the girdle) of thediamond. Similarly, the crown angle is also within the range set forthin Table 2. The crown 124 and pavilion 126 portions of the cushionshaped, shallow pavilion diamond 120 are separated by a narrow girdleportion 132. The girdle 132 shown in FIG. 9 is multi-faceted with tinyfacets approximating rounded cushion shape, but girdle may also be asmooth polished cushion shape (not shown).

More specifically, as can be seen in FIGS. 7-9, the shallow pavilion,cushion shaped diamond 120 of the invention is comprised of a total of64 facets. The crown 124 has 37 facets including a single table facet122, eight bezel facets 121, twelve star facets 123, and sixteen uppergirdle facets 125. The pavilion 126 comprises a total of twenty sevenfacets including twenty lower girdle facets 127, six main pavilionfacets 129, and a single pointed culet 130 as best seen in FIG. 8. Thecrown angle is measured between the surface of each of the bezel facets121 and the plane of the table 122 (average of each measured angle forthe bezel facets). The pavilion angle is measured between the plane ofthe table 122 and main pavilion facets 129. The pointed culet 130 may bea less than razor sharp such as shown with shallow angle pointed culet130 shown in FIG. 9. Alternately, the pavilion 126 may narrow to asharper pointed culet 130 that is a “true point,” that is, a very sharppoint (not shown).

FIG. 7A illustrates an alternate crown facet arrangement for a cushionshaped, shallow pavilion diamond of the invention. The alternate crown124A includes table facet 122A, eight bezel facets 121A, fourteen starfacet 123A, and sixteen upper girdle facets 125A. FIGS. 7C and 7Dsimilarly illustrate additional alternate crown facet arrangement forshallow pavilion, cushion cut diamonds of the invention. Crowns 124C,124D each have a single table facet 122C, 122D; four bezel facets 121C,121D; eight star facets 123C, 123D; and eight upper girdle facets 125C,125D, respectively. The crown angle, crown height, girdle height for thealternate crowns 124A, 124C, 124D are within the parameters set for inTable 2.

FIGS. 7B and 8B illustrate a more elongated shallow pavilion, cushioncut diamond 120B in accordance with the invention. The shallow pavilion,cushion cut diamond 120B has a crown 124B having a single table facet122B, ten bezel facets 121B, sixteen star facets 123B, and twenty uppergirdle facets 125B. The pavilion 126B comprises a total of twenty-ninefacets including twenty lower girdle facets 127B, eight main pavilionfacets 129B, and a pointed culet 130B. The crown angle, crown height,girdle height, pavilion angle, table percentage, and total depthpercentage for the shallow pavilion, cushion cut diamonds 120 and 120Bare all within the parameters set for in Table 2 above.

The present inventor has discovered that a brilliant-like reflectionpattern can be obtained by providing a cushion shaped, cut diamond andother fancy cut diamond shapes with a shallow pavilion angle combinedwith a pointed culet at the bottom of the pavilion. The pavilion anglesfor the fancy cut diamonds of the invention range between twenty five tothirty four and one half degrees, preferably between thirty to thirtytwo degrees. By utilizing the combination of a pointed culet and shallowpavilion angle in accordance with the fancy cut diamonds of theinvention realizes improved brilliance and light amplificationcharacteristics relative to traditional steep pavilion angle fancy cutdiamonds of the prior art. The maximum and minimum crown angles for theshallow pavilion, fancy cut diamonds of the invention are between abouttwenty nine degrees and about thirty four and one half degrees. Thecrown angle for the shallow pavilion, fancy cut diamonds of theinvention are preferably in the range of from thirty and thirty fivedegrees.

By adhering to the criteria set forth in the Table 2, the light patternfor shallow pavilion, fancy cut diamonds 120, 120B, 220, 220A, 320 and420 of the invention, follows a path whereby light is reflected from onepavilion surface to an opposed crown surface, then to another pavilionsurface, then to the table, then back to a pavilion surface, then to thecrown, then to an opposed pavilion surface and only then out to thetable in a manner similar to that shown above in FIG. 6 for the round,shallow pavilion diamond 20 of the invention. This light pattern withlight rays being repeatedly reflected and refracted between manyinternal diamond surfaces of the shallow pavilion diamond of theinvention creates an extremely brilliant light display when compared totraditional deep pavilion, fancy diamonds. As a result of the repeatedreflection and refraction, the light transmitted from the table of theshallow pavilion, fancy cut diamonds 120, 120B, 220, 220A, 320, and 420is quite brilliant and is visually similar to that measured for theround, shallow pavilion diamond 20 of the invention discussed above andillustrated in FIG. 6.

FIGS. 10-12 illustrate a heart shaped, shallow pavilion diamond 220 inaccordance with the invention. The heart shaped, shallow paviliondiamond 220 has a table 222, a crown 224 extending downwardly from thetable 222, a girdle 232 located below the crown 224, and a pavilion 226extending downwardly from the girdle 232. The pavilion 226 surfacenarrows in width to a pointed culet 230. FIG. 12 shows that the pavilion226 extends at a shallow pavilion angle within the range set forth inTable 2 relative to the plane of the table (or to a line parallel to thetable passing through the girdle) of the diamond. Similarly, the crownangle is also within the ranges listed in Table 2. The crown 224 andpavilion 226 portions of the heart shaped, shallow pavilion diamond 220are separated by a narrow girdle portion 232. The girdle 232 best seenin FIG. 12 is a smooth polished heart shaped band, but may also bemulti-faceted with tiny facets approximating a heart shaped band (notshown).

The heart shaped, shallow pavilion diamond 220 of the invention iscomprised of a total of 56 facets. The crown 224 has 32 facets includinga single table facet 222, eight bezel facets 221, eight star facets 223,and fifteen upper girdle facets 225. The pavilion 226 comprises a totalof twenty four facets including sixteen lower girdle facets 227, sevenmain pavilion facets 229, and a single pointed culet 230 as best seen inFIGS. 10 and 12. The crown angle is measured between the surface of eachof the bezels facets 221 and the plane of the table 222 (average of eachmeasured angle for the bezel facets). The pavilion angle is measuredbetween the plane of the table 222 and main pavilion facets 229. Thepointed culet 230 may be a less than sharp such as shown with slightlypointed beveled culet 230 shown in FIGS. 11-12. Alternately, thepavilion 226 may narrow to a pointed culet that is a “true point”, thatis, a very sharp point (not shown).

FIG. 10A illustrates an alternate facet configuration for a shallowpavilion, heart shaped diamond 220A in accordance with the invention.The shallow pavilion, heart shaped diamond 220A has a total of 52facets. The crown 224A has 35 facets including a single table facet222A, nine bezel facets 221A, nine star facets 223A, and sixteen uppergirdle facets 225A. The pavilion 226A comprises a total of twenty-sevenfacets, including eighteen lower girdle facets 227A, eight main pavilionfacets 229A, and a single pointed culet 230A. The shallow pavilion,heart shaped diamond of FIGS. 10 and 10A have crown angles, crownheights, girdle heights, pavilion angles, table width percentage, andtotal depth percentage within the parameters set forth in Table 2.

FIGS. 13-16 illustrate a pear shaped, shallow pavilion diamond 320 ofthe invention. The pear shaped cut diamond 320 has a table 322, a crown324 extending downwardly from the table 322, a girdle 332 located belowthe crown 324, and a pavilion 326 extending downwardly from the girdle332. The pavilion 326 surface narrows in width to a pointed culet 330.FIGS. 15-16 show that the pavilion 326 extends at a shallow pavilionangle within the parameters set forth in Table 2 relative to the planeof the table (or to a line parallel to the table passing through thegirdle) of the diamond. Similarly, the crown angle is within theparameters set forth in Table 2 above. The crown 324 and pavilion 326portions of the cushion, cut diamond 320 are separated by a narrowgirdle portion 332. The girdle 332 best seen in FIG. 15-16 is a smoothpolished pear shaped band, but may also be multi-faceted with tinyfacets approximating a pear shaped band (not shown).

The pear shaped, shallow pavilion diamond 320 of the invention iscomprised of a total of 56 facets. The crown 324 has 33 facets includinga single table facet 322, eight bezel facets 321, eight star facets 323,and sixteen upper girdle facets 325. The pavilion 326 comprises a totalof 23 facets including sixteen lower girdle facets 327, six mainpavilion facets 329, and a single pointed culet 330 as best seen inFIGS. 14-16. The crown angle is measured between the surface of each ofthe bezel facets 321 and the plane of the table 322 (average of eachmeasured angle for the bezel facets). The pavilion angle is measuredbetween the plane of the table 322 and main pavilion facets 329. Thepointed culet 330 may be a less than sharp such as shown with pointedculet 330 shown in FIGS. 13-16. Alternately, the pavilion 326 may narrowto a more sharply pointed culet (not shown). FIG. 14A illustrates analternate pavilion facet arrangement for use in a pear shaped, shallowpavilion diamond of the invention. The alternate pavilion 326A comprisesa total of 21 facets including sixteen upper girdle facets 327A, fourmain pavilion facets 329A and one pointed culet 330A. The crown angle,crown height, girdle height, pavilion angle, table percentage, and totaldepth percentage of the pear shaped, shallow pavilion diamond 320 andthe pavilion angle, table width percentage, and total depth percentagefor the alternate pavilion 326A all fall within the parameters set forthin Table 2.

FIGS. 17-20 illustrate an oval shaped, shallow pavilion diamond 420 ofthe invention. The oval shaped cut diamond 420 has a table 422, a crown424 extending downwardly from the table 422, a girdle 432 located belowthe crown 424, and a pavilion 426 extending downwardly from the girdle432. The pavilion 426 surface narrows in width to a pointed culet 330.FIGS. 19-20 show that the pavilion 426 extends at a shallow pavilionangle within the parameters set forth in Table 2 relative to the planeof the table (or to a line parallel to the table passing through thegirdle) of the diamond. Similarly, the crown angle is within theparameters set forth in Table 2 above. The crown 424 and pavilion 426portions of the oval shaped, shallow pavilion diamond 420 are separatedby a narrow girdle portion 432. The girdle 432 best seen in FIGS. 19-20is a smooth polished oval shaped band, but may also be multi-facetedwith tiny facets approximating an oval shaped band (not shown). Thecrown angle, crown height, girdle height, pavilion angle, table widthpercentage, and total depth percentage of the oval shaped, shallowpavilion diamond 420 fall within the parameters set forth in Table 2.

The oval shaped, shallow pavilion diamond 420 of the invention iscomprised of a total of 58 facets. The crown 424 has a total of 33facets including a single table facet 422, eight bezel facets 421, eightstar facets 423, and sixteen upper girdle facets 425. The pavilion 426comprises a total of twenty-five facets including sixteen lower girdlefacets 427, eight main pavilion facets 429, and a single pointed culet430 as best seen in FIGS. 18-20. The crown angle is measured between thesurface of each of the bezel facets 421 and the plane of the table 422(average of each measured angle for the bezel facets). The pavilionangle is measured between the plane of the table 422 and main pavilionfacets 429. The pointed culet 430 may be a less than sharp such as shownwith pointed culet 430 shown in FIGS. 19-20. Alternately, the pavilion426 may narrow to a more sharply pointed culet (not shown). The crownangle, crown height, girdle height, pavilion angle, table widthpercentage, and total depth percentage of the oval shaped, shallowpavilion diamond 420 fall within the parameters set forth in Table 2.

Although the present invention has been described in relation toparticular embodiments thereof, many other variations and modificationsand other uses will become apparent to those skilled in the art. It ispreferred, therefore, that the present invention be limited not by thespecific embodiments disclosed herein, but only by the appended claims.

We claim:
 1. A cut diamond having a round shape, the cut diamondcomprising: a table having a table plane and a substantially annulargirdle, the cut diamond having a shape and configuration that results ina specific total depth percentage, a specific crown height percentage, aspecific girdle height percentage and a specific table percentage; acrown surface located between the table and the substantially annulargirdle and extending in a crown angle to the table plane; a pointedculet defining the bottom most portion of the cut diamond; at leastthree pavilion surfaces, each extending at a pavilion angle relative tothe table plane; and, wherein the crown angle is in the range of 29degrees to 36 degrees and the pavilion angle is in the range of 25degrees and 36 degrees.
 2. The round cut diamond of claim 1 wherein thetotal depth percentage is in the range of 25 percent to 50 percent. 3.The round cut diamond of claim 1 wherein the table diameter is in therange of 55 percent to 85 percent.
 4. The round cut diamond of claim 1wherein the crown height is in the range of 7 percent to 15 percent. 5.The round cut diamond of claim 2 wherein the total depth percentage isin the range of 35 percent to 47 percent.
 6. The round cut diamond ofclaim 3 wherein the table diameter is in the range of 66.5 percent to 85percent.
 7. The round cut diamond of claim 4 wherein the crown height isin the range of 9 percent to 12 percent.
 8. The round cut diamond ofclaim 1 wherein the pavilion angle is in the range of 30 degrees to 33degrees.
 9. A fancy cut diamond comprising: a table having a table planeand having a non-circular circumference girdle, the cut diamond having ashape and configuration that results in a specific total depthpercentage, a specific crown height percentage, a specific girdle heightpercentage and a specific table percentage; a crown surface locatedbetween the table and the girdle having a non-circular circumference andextending in a crown angle to the table plane; at least three pavilionsurfaces, each extending at a pavilion angle relative to the table, thepavilion surfaces include a plurality of substantially planar mainpavilion facets, each of the plurality of substantially planar mainpavilion facets extend from the girdle having a non-circularcircumference to a pointed culet defining the bottom most portion of thecut diamond; and, wherein the crown angle is in the range of 29 degreesto 36 degrees and the pavilion angle is in the range of 15 degrees and34.5 degrees.
 10. The fancy cut diamond of claim 9 wherein the pavilionangle is in the range of 22 degrees to about 33 degrees.
 11. The fancycut diamond of claim 9 wherein the table diameter is in the range of 60percent to about 85 percent.
 12. The fancy cut diamond of claim 9wherein the diamond has a pear shape.
 13. The cut diamond of claim 9wherein the diamond has a cushion shape.
 14. The fancy cut diamond ofclaim 9 wherein the diamond has a heart shape.
 15. A cut diamondcomprising: a table having a table plane and a girdle, the cut diamondhaving a shape and configuration that results in a specific total depthpercentage, a specific crown height percentage, a specific girdle heightpercentage and a specific table percentage; a crown surface locatedbetween the table and the girdle and extending in a crown angle to thetable plane; at least four pavilion surfaces, each extending at apavilion angle relative to the table, the pavilion surfaces includes aplurality of substantially planar main pavilion facets, each of theplurality of substantially planar main pavilion facets extend from thegirdle to a pointed culet defining the bottom most portion of the cutdiamond; and, wherein the crown angle is in the range of 29 degrees to36 degrees and the pavilion angle is in the range of 15 degrees and 34.5degrees.
 16. The cut diamond of claim 15 wherein the total depth is inthe range of 25 percent to 55 percent.
 17. The cut diamond of claim 15wherein the table percentage is in the range of 50 percent to 90percent.
 18. The cut diamond of claim 15 wherein the crown height is inthe range of 7 percent to 15 percent.
 19. The cut diamond of claim 15wherein the pavilion angle is in the range of 22 degrees and about 33degrees.
 20. The cut diamond of claim 15 wherein the diamond has a roundshape.
 21. The cut diamond of claim 15 wherein the diamond has an ovalshape.